Been following this for a while, It has all the features the Porsche should have had (especially that luggage bag ;) ). I really think the official TLG Technic team could learn a lot from this build.
I just had a look at the instructions, and can't wait to start building this beauty. I like that you have supplied instructions for the chassis on their own. I wonder what supercars would fit it's wheelbase if you were to just build the chassis.
Also, I noticed a linear clutch beneath the rear differential (Step 47). Does this mean its some form of limited slip mechanism for the center diff?